Variable-Granularity Tokenization for High-Resolution Object Detection

ViT detectors fix a uniform token grid before any learned stage. A native-resolution aerial detector must then choose between resolving few-pixel objects and staying inside compute and memory limits. We introduce VGTok, a training-free tokenizer that sets patch granularity per region from pixels, ahead of the encoder. VGTok scores each region by multi-scale morphological top-hat separability from its surround, then thresholds those scores at a per-image percentile, which fixes the token budget. A structure-tensor gate (λmin) refines only where two-dimensional object structure supports it, leaving one-dimensional clutter coarse. The resulting token set is a strict partition of the image. In a Co-DETR detector with an EVA-02 ViT-L encoder, VGTok clears every published VisDrone-val AP and APS at every budget from 40% to 100% of tokens. At 40% it records 44.22 AP with three fifths of the sequence discarded before the first transformer block; dense, it reaches 48.38 AP, 6.08 above the strongest published entry. VGTok transfers to AI-TOD-v2 untouched, same scorer and same rank, and sets a new state of the art at 37.27 AP and 19.51 APvt. As a pure drop-in into a frozen checkpoint it reaches 36.29 AP at 78.5% of tokens, above every published entry, where our 376.3M-parameter detector clears a 3.0B multi-expert model. We show that a token budget fixed before the backbone, from local separability and structure geometry alone, holds accuracy on the tiny-object regimes that dominate aerial detection, at 3.1× less encoder compute and 1.9× less encoder memory. Code and models are available at hrefhttps://github.com/khayrulbuet13/vgtoktextttgithub.com/khayrulbuet13/vgtok and hrefhttps://huggingface.co/khayrulbuet13/vgtoktexttthuggingface.co/khayrulbuet13/vgtok.